Blanks for Containers

ABSTRACT

A blank from which may be erected a protective enclosed tamper evident container for the packaging of articles during transportation and storage has five aligned panels that form opposed roof and floor walls having a dome shape connected at opposite ends of the container by side walls having a concave shape. The centre panel forming the floor wall has opposed closure panels that fold over the roof wall to close the open sides of the container and are provided with locking tongues that engage slots in the roof wall to secure the container. The tongues and slots provide a tamper evident mechanism for securing the container such that no adhesive is required during the erection process in order to hold the container in its closed position.

This invention relates to blanks for containers, and in particular, but not exclusively, a blank for a protective enclosed tamper evident container and such a container made therefrom.

Many designs of blank made from sheet materials and then formed or folded into an assembled container, have been proposed to protect the contents from damage during storage, handling and transport. Some designs have used the architecture of the container to provide increased strength over that of the material from which they are made.

In British Patent Specifications Nos: 2,315,060 and 2,342,343, there are described two different types of container blank which are especially suitable for the packaging of fluids contained within a plastic bag. These blanks have arcuate crease lines, and when erected, form pillow shaped containers, with arcuate panels providing strength and durability to the assembled container.

The sleeve-like containers disclosed in these British Patent Specifications have open ends and must be transported in a “sleeping” position in order to prevent the contents from falling out of one or other end of the sleeve. In turn, this means that either of these sleeve-like containers require to be transported in a shipping container such as a carton box, typically made from heavier duty corrugated fibreboard.

Two different changes in the market place have made it necessary to consider improvements to these blanks and the containers made therefrom described in the earlier British Patent Specifications listed above. Firstly, new legislation and increasing environmental pressure is resulting, amongst other things, in a need to eliminate unnecessary layers of packaging. Secondly, there is an increasing requirement for tamper evident packaging to highlight interference with goods during storage and carriage.

The present invention seeks to provide an improved form of blank for forming a container and a container assembled from such blank.

In a first aspect, the present invention provides a blank from which may be formed a protective enclosed tamper evident container, the blank being made of shape-retaining material and comprising a main section which has five aligned panels, a first of these panels defining a first main wall of the container, second and third of these panels, each defining a side wall of the container, are connected to opposite ends of said first panel, fourth and fifth of these panels, each defining a portion of a second main wall of the container, are connected to said second and third panels at an end that opposes the end connected to said first panel, wherein the second main wall is, when erected, opposed to the first main wall, with said fourth and fifth panels being dimensioned to overlap free end of one panel over free end of the other panel, the side wall panels are defined between first and second arcuate crease lines curved towards each other such that each side wall panel is almost elliptical, and the blank includes a closure panel on each side of the main section, wherein each closure panel is provided with a tongue that is, when the container is erected, received in a respective matching slot provided in one of the main walls of the container in order to hold the container in a closed position, and each slot being so shaped and dimensioned that, once entered, neither tongue can be removed without leaving evidence of tampering, and in which no adhesive is required during the erection of the blank in order to hold the container in its closed position.

This aspect of the invention provides an alternative form of blank with arcuate crease lines that may easily be erected into a protective enclosed tamper evident container without the use of any adhesive being required to hold the resulting container together in its erected form. The arcuate crease lines form side walls of concave shape that provide the container with inherent impact resistance and mechanical strength.

In one arrangement, this aspect of the invention provides a blank in which the crease lines on both aligned edges of a first panel defining a first main wall are made in a curvilinear shape so that the erected container assumes a pillow shape, while the other two edges of this first panel bear closure panels each of which carries at its free end a tongue in the shape of an arrow head that in use co-operates with a matching slot/slit combination in a panel of a second main wall of the blank opposed to the first main wall.

In another arrangement, this aspect of the invention provides a blank in which the crease lines on both aligned edges of a first panel defining a first main wall are made in a curvilinear shape so that the erected container assumes a pillow shape, while the two opposed edges of the outermost panel of the second main wall bear closure panels each of which carries at its free end a tongue in the shape of an arrow head that in use co-operates with a matching slot/slit combination in the panel defining the first main wall of the blank opposed to the second main wall.

Preferably, the blank is made of shape-retaining material and is generally a paper product, preferably corrugated fibre board. However, other materials, may be used, including all types of corrugated board, single or double face, solid paperboard such as folding boxboard, extruded plastic sheets such as those made from polyethylene, extruded plastic cellular sheets such as those known by the trade name “CORREX”™, laminated materials of all kinds including those containing aluminium foil, and composite materials.

A preferred material, though, is a single-wall “B” flute corrugated fibre board material made from recycled materials, although it will be understood that the fluting media used may vary depending on the nature of the product to be packaged and the strength required in the container. Indeed, whilst numerous other materials and combinations of fluting medium could be utilised, the material known by the trade name “TEST” is particularly preferable since it is made from recycled material and is therefore inherently weaker than a pure kraft (virgin) construction. This is a desirable feature, as a container made therefrom, when erected and subjected to mechanical shocks, affords much greater resilience (cushion factor) and energy-absorbing characteristics.

Where the material used for the blank of the invention is fluted board, the fluting is preferably aligned generally from end to end of the blank (and thus generally normal to the arcuate crease lines). This gives increased shock-absorbing and inherent strength properties to the container made therefrom.

The blank has aligned panels defining first and second opposed main walls of the container, between which, and defined by first and second crease lines at opposed ends of the container, are two opposed side walls of the container. Each of these crease lines is arcuate, the sense of the arc—bowed in or bowed out—being such that the side walls are generally correspondingly almost elliptical. It is this which causes the container erected from the blank to take on the desired pillow shape.

It may be convenient, depending on the material from which the blank is made, to perforate the crease lines by the use of lasers or otherwise, firstly to render easier the folding of the blank (especially as the degree of curvature of the arcuate crease lines increases), and secondly to make the resulting container crumple and so absorb shock more readily.

Thus, the arcuate nature of the crease lines defining the elliptical side walls is preferably such that the heights between the arcuate crease lines at their centres—the centre point heights—and between the same arcuate crease lines at their outer limits—the outer limit heights—are generally in a ratio of centre point height:to outer limit height of 100:1 or less. A preferred range is from 4:1 down to 1.5:1, and in one example the ratio is 2:1. It might also be worth observing that the greater the degree of curvature, the more the erected container will be “waisted” as well as “rounded”.

The slots are shaped and dimensioned to retain the tongues in place, and to stop them being subsequently removed without leaving evidence of tampering. This can be achieved by arranging that each slot is partly die cut and partly slit such that the width of the arrow head tongue is approximately the same as the overall length of the slit. In this way, a degree of force is required to press the arrow head tongue through the slot, and once inserted, the die cut slot is not sufficiently wide to allow the arrow head tongue to be withdrawn without obvious damage to the tongue or to the area of the container surrounding the slots.

If the blank has been appropriately dimensioned, the arcuate nature of the erected container allows the contents of the container to become clamped as the arrow shaped tongues are pushed through the slots into their locked position, thereby preventing the contents from movement during storage or transport.

In another embodiment, the blank is made from one of the materials described above, to the inside surface of which has been attached by whatever means is considered most appropriate, an insulating or further protecting layer such as a foamed material, bubble wrap, cradle wrap or other filmic materials incorporating sealed bags or bubbles containing air or other gases. In this context, it will be understood that the inside surface of the blank means that surface which will become the inside surface of the container after erection.

In this way, and again if the blank has been appropriately dimensioned, as the arrow shaped tongues are pushed through the slots into their locked position, the contents of the container will become even more tightly clamped due to the elasticity of the insulating or further protecting layer.

In a second aspect, the present invention provides a blank designed to be assembled into a container having opposing roof and floor faces and a plurality of between three and eight side wall faces of which the wall faces are two dimensionally concave intersecting in plan view to form acute angled corners and in side elevation to form substantially elliptical shapes, and the two opposing roof and floor faces have a three dimensionally convex domed shape, such that all faces of the assembled container are curved in at least two dimensions.

This aspect of the invention provides a blank which, once assembled into a container, may provide greater strength and resistance to damage of the contents of the container, in all three dimensions and may provide equally high strength around the entire periphery. This may be achieved without sacrificing simplicity of manufacture of the blank, or ease of assembly and closure of the container.

The blank is produced by cutting and creasing a sheet material that is rigid enough to maintain its shape after assembly but flexible enough to be readily creased and folded. The blank is preferably made from corrugated material although any foldable material may be used. If the material is difficult to fold, it can be assisted by perforating along the fold lines by blade point, by laser, or by any other method known to persons skilled in the art. Preferably, corrugated fibreboard is used, having a weight of 100-300 grams per square metre (gsm), typically 125-190 gsm.

The corrugated fibreboard may be of any fluting format, single wall (including microflutes), double, or triple wall, which lends itself easily to cutting and creasing. It must be noted however that other flat sheet materials can be used to manufacture the blank according to this invention, such as extruded plastic corrugated sheet, (for example, that known as “CORREX”™), paper carton board, paper folding box board, lightweight metals and various mono or multi-laminated polymeric sheets.

It may be convenient, depending on the material from which the blank is made, to perforate the crease lines by the use of lasers or otherwise, firstly to render easier the folding of the blank (especially as the degree of curvature of the arcuate crease lines increases), and secondly to make the resulting container crumple and so absorb shock more readily.

The inside surface of the blank may be provided with a layer of an insulating material and/or a further protecting material such as a foamed material, bubble wrap, cradle wrap or other filmic materials incorporating sealed bags or bubbles containing air or other gases.

When assembled from the blank according to this aspect of the invention, a typical container has opposing roof and floor faces and a plurality of wall faces extending therebetween, of which the wall faces take a two dimensional concave form and the opposing roof and floor faces take a three dimensional convex domed shape offering particular strength to the container. Thus, a particular feature of the invention is that all faces of the assembled container are curved in at least two dimensions.

In one preferred embodiment, the container has four concave wall faces but this is not essential and the container may have fewer wall faces, for example three, or more wall faces, for example from five to eight. In this preferred embodiment having four concave wall faces, the blank may be assembled into a container that is square in outline or into a container that is rectangular in outline.

Preferably, the blank is configured so that, after assembly, the radius of each of the concave wall faces is such that the assembled containers can fit together to form a stable stack. The blank may be configured so that, after assembly, the concave wall faces extend between the opposing convex floor and roof faces around the entire periphery of the assembled container. The curvature of both arcuate crease lines of any panel is preferably identical.

In at least one embodiment, the blank is configured so that, after assembly, container can provide maximal protection and shock resistance of the contained volume per unit area of sheet material from which the blank is made due to the plurality of concave vertical wall faces and opposing convex domed roof and floor faces. For example, the contents of the assembled container can be protected from external impact or pressure in a horizontal direction by means of the container's acute angled corners, and similarly protected in a vertical direction by means of the opposing convex domed roof and floor faces.

In a preferred embodiment, the dimensions of the blank are chosen so that the contents of the assembled container are in contact with the centre of each concave wall face and the corners are preferably free to deform or collapse thereby sacrificially absorbing or dissipating impacts and protecting the product.

Preferably, the blank is configured so that the acute angled corners of the assembled container define a progressively narrowing space in a direction away from the container's geometric centre such that any movement of the contents causes the contents to make contact with an internal surface of the container which is at an incline to the direction of motion causing gradual deceleration of the contents, reducing shock and therefore damage to the contents.

In at least one embodiment, the blank may be configured so that the fluting of the corrugated material is disposed at 45 degrees to the longitudinal direction of the blank in each concave vertical wall face such that the strength in a vertical direction of all wall faces is equal.

Preferably, the blank is configured in such a way that, for corrugated material, the fluting direction of all the concave wall faces is in a vertical direction. In one embodiment, the blank may comprise two or more parts in which successive parts are placed upon the first part at angles not greater than 90 degrees to each other so that, for corrugated material, the fluting direction of all the concave wall faces is in a vertical direction thereby providing maximum vertical strength.

The blank may include flaps provided as extensions to any or all of the panels of the blank that can be folded to provide the assembled container with internal supports to restrain the movement of the contents within the closed container or to provide internal structural support to the faces of the container.

In a third aspect, the present invention provides a blank having a plurality of panels for erecting an enclosed container having opposed main walls and a plurality of side walls, and tamper evident means for securing the container in an assembled condition enclosed on all sides.

Preferably the tamper-evident means comprise at least one locking tongue that is inserted in a locking slot wherein the tongue and slot are configured so that once inserted, the tongue cannot be removed without leaving evidence of tampering. The tongue may be of arrow shape and the slot may be part die cut and part slit to allow insertion of the tongue and resist removal.

The main walls preferably provide the container with opposed roof and floor walls of curved shape, preferably convex, and side walls of arcuate shape, preferably concave. The container may be pillow shaped or dome shaped.

Preferably, the blank has a first section comprising five aligned panels that form the main walls of the container and a pair of side walls at opposite ends of the container, and a second section with panels that close open sides of the container between the side walls of the first section.

The first and second sections may be formed integrally in one piece or as two separate parts that are laid one on top of the other during assembly of the container.

In a fourth aspect, the invention provides a blank for erection of a container, the blank having five aligned panels of which the first, third and fifth panels form opposed main walls of the container and the second and fourth panels form opposed side walls at opposite ends of the container, and at least two panels arranged to close the container between the ends.

Preferably, the second and fourth panels are defined by arcuate crease lines at the edges adjoining the first, third and fifth panels such that the side walls are of arcuate concave shape in plan view in the assembled container.

In one arrangement, the at least two panels that close the container between the ends are connected to opposite sides of the third panel along straight crease lines such that, during assembly, these panels fold over the first and fifth panels and are secured in a tamper-evident manner.

In a fifth aspect, the invention provides a protective enclosed tamper evident container made by erecting a blank according to any of the preceding aspects of the invention.

This aspect of the invention provides a protective enclosed tamper evident container capable of being stored and transported without a further layer of packaging such as a shipping container around it, using arcuate crease lines to provide the container with impact resistance in all dimensions, and capable of being erected without the use of any adhesive.

Moreover, whilst this invention was conceived with the transport of fragile articles in mind, any articles susceptible to shock, or any application requiring ease of erection without the need for adhesive, could equally benefit from its principles.

What the invention proposes is a containerisation system which offers protection of a packaged article against mechanical shock, ease of erection, and detection of tampering during storage and transport.

To achieve these aims, the invention suggests the use of a novel construction of arcuate blank that may be folded and then erected into a protective tamper evident arcuate folded container enclosed on all sides so that the contents cannot fall out as they were able to do from the open ends of the sleeve-like containers described in the earlier inventions and yet offer a similar ability to withstand and cushion the contents of the container against physical shocks associated with normal conditions of transport, storage and use.

The corrugated material forming the blank may be arranged so that, in the assembled container, the fluting in the side wall panels extends between the main panels to resist crushing of the container.

The closure panels may be connected to the first main panel by side wall panels of arcuate shape so that the assembled container has four concave side walls extending between opposed convex dome-shaped main panels. The main panels may form the roof and floor of the container.

The invention is now described, by way of illustration only, with reference to the accompanying drawings in which like reference numerals are used throughout to indicate corresponding parts and wherein:

FIG. 1 shows a blank according to a first embodiment of the present invention for assembly of a tamper evident container;

FIG. 2 shows the blank of FIG. 1 partially assembled;

FIG. 3 shows a plan view of the erected container illustrating the tongues in their locked position;

FIG. 4 shows a modification to the blank of FIG. 1;

FIG. 5 shows a blank according to a second embodiment of the present invention for assembly of a tamper evident container;

FIG. 6 shows the blank of FIG. 5 partially assembled;

FIG. 7 shows a plan view of the erected container illustrating the tongue in its locked position;

FIG. 8 shows a perspective view of the erected container of FIG. 7;

FIG. 9 shows a two-part blank according to a third embodiment of the present invention for assembly of a tamper evident container;

FIG. 10 shows a modification to the two-part blank of FIG. 9; and

FIG. 11 shows a blank according to a fifth embodiment of the present invention for assembly of a tamper evident container.

Referring first to FIGS. 1 to 3 of the accompanying drawings, a blank 1 according to a first embodiment of the invention is shown in FIG. 1 having five aligned panels (A, B, C, D, E) for assembly of a tamper evident container 2 shown in FIG. 3.

The container 2 has a first side wall formed by the panel B that is defined on either side by arcuate crease lines 3,4. Similarly, the container 2 has a second side wall formed by the panel D that is defined on either side by arcuate crease lines 5,6. In the case of both side walls B and D, the arcuate crease lines 3,4 and 5,6 respectively are curved towards each other such that the side walls are almost elliptical.

The container 2 has a bottom or main wall formed by the centre panel C and an opposed top or main wall formed by the panels A and E. The bottom wall panel C extends between and has opposed edges defined by the arcuate crease lines 4,5 connected to the side wall panels B,D respectively. The top wall panels A,E have one edge defined by the arcuate crease lines 3,6 connected to the side wall panel B,D respectively and opposed free edges that overlap one another.

The other edges of the centre panel C are defined by two straight crease lines 7,8 which are parallel to each other. The crease lines 7,8 define one edge of two wing or closure panels F,G. The other three edges of the wing panels F,G are defined by lines 9, 10 and 11.

Attached to both wing panels F,G are locking tongues H. These locking tongues H are arrow shaped to facilitate erection of the container and have square die cut heads defined by lines 12, 13 and angled side edges defined by lines 14,15. The top wall panel E is provided with two parallel slots 16 to receive the tongues H. The tongues H and slots 16 provide tamper-evident formations that provide a visual indication if the container 2 has been opened.

Assembly of the container 2 from the blank 1 will now be described.

In a first operation, side wall panel B is folded around line 4 and top wall panel A is folded around line 3 such that top wall panel A extends partially across bottom wall panel C as shown in FIG. 2.

In a second operation, side wall panel D is folded around line 5 and top wall panel E is folded around line 6 and then laid over top wall panel A creating a pillow shape container 2 with opposed concave side walls B and D, and opposed convex bottom and top walls C and A,E. As shown the free end of the panel E is of arcuate shape to match the curved shape of the side wall B.

In a third and fourth operation, each wing panel F,G is folded at crease lines 7,8 and laid over top wall panel E to close the open sides of the container 2 so that any article packed within the container 2 is already prevented from falling out.

In a fifth and sixth operation, the wing panels F,G are locked in place by inserting the arrow shaped locking tongues H through the slots 16 in the top wall panel E. The slots 16 are in part die cut 17 and in part slit 18 so that, when the arrow shaped locking tongues H are pushed through the slots 16, the tongues H are secured by the square cut outs defined by lines 12 and 13 which hold against the slots 16 (FIG. 3).

In this embodiment, the blank 1 is made of shape retaining material such as corrugated cardboard in which the fluting (not shown) extends parallel to the length of the blank, i.e. longitudinally from one end to the other, and is generally perpendicular to the crease lines 3,4,5,6. In this way, the fluting extends between the bottom and top walls of the assembled container 2 and provides increased shock-absorbing and inherent strength properties to the container. This is not essential however, and the fluting may extend at an angle to the longitudinal direction of the blank 1 to vary the shock-absorbing and strength properties of the container 2 as desired.

In a modification (not shown), the wing panels F,G are connected to opposed edges of the top wall panel E and the slots 16 are provided in the bottom wall panel C to receive the locking tongues H when the wing panels F,G are folded over to close the open sides of the container 2. Alternatively, the bottom wall panel C may have wing panel F and the top wall panel E may have wing panel G with locking tongue H of wing panel F received in the slot 16 in top wall panel E and locking tongue H of the wing panel G received in the slot 16 in the bottom wall panel C.

Referring now to FIG. 4, there is shown another modification to the design of the blank 1 shown in FIG. 1. In this modification, the parallel crease lines 7,8 at either edge of the centre panel C are replaced by arcuate crease lines 19,20 that define side wall panels J and K between the bottom wall panel C and the wing panels F,G.

In this modification, when the blank 1 is erected to form a container, the side wall panels B,D,J,K form concave side walls around the entire perimeter of the container and the bottom wall panel C and top wall panels A,E form domed convex top and bottom walls. As shown, the free edges of the top wall panel E are curved to match the curved shape of the side walls formed by the side wall panels B,J,K.

The wing panels F,G are locked in place by inserting the arrow shaped locking tongues H in the slots 16 in the top wall panel E as described previously. In a modification (not shown), the side wall panels J,K and wing panels F,G may be provided on opposed edges of the top wall panel E with the slots 16 provide din the bottom wall panel C to receive the locking tongues H. Alternatively, the bottom wall panel C and top wall panel E may each have one side wall panel and wing panel and one slot/

In this embodiment, the blank 1 is made of shape retaining material such as corrugated cardboard in which the fluting (not shown) extends parallel to the length of the blank, i.e. longitudinally from one end to the other, and is generally perpendicular to the crease lines 3,4,5,6.

In this way, the fluting of the side panels B,D extends between the bottom and top walls of the assembled container 2 and the fluting of the side wall panels J,K extends generally parallel to the bottom and top walls. As a result, the shock-absorbing and inherent strength properties of the side wall panels B,D are different to those of the side wall panels J,K.

In a modification, the fluting extends at 45° to the longitudinal direction of the blank 1 so that the shock-absorbing and strength properties of the side walls B,D,J,K are the same. The direction of the fluting may be altered as desired to provide the container with any required shock-absorbing and strength properties.

Referring now to FIGS. 5 to 8 of the drawings, a blank 1 according to a second embodiment of the invention is shown in which the locking mechanism for securing the container 2 erected from the blank 1 in the assembled condition is altered.

In this embodiment, the two arrow shaped locking tongues H on the wing panels F,G are replaced with a single arrow shaped locking tongue H on the free edge of the top wall panel E remote from the side wall panel D and the slots 16 in the top wall panel E are replaced by a single slot 16 formed at the junction of top wall panel A and side wall panel B.

Assembly of the container 2 from the blank 1 shown in FIG. 5 will now be described.

The contents to be packed within the container are first placed upon bottom wall panel C. Opposed side wall panels J,K and wing panels F,G are folded along their respective arcuate crease lines 19,20 to form opposed side walls of concave shape with wing panels F,G folded over to form a partial roof over the contents.

Side wall panels B,D are then folded along the respective arcuate crease lines 4,5 to form opposed side walls of concave shape as shown in FIG. 6. Top wall panel A is then folded along crease line 3 to extend over the wing panels F,G at one end of the container 2 and reveal the locking slot 16 into which the arrow shaped locking tongue H on the top wall panel E is to be inserted.

The slot 16 is only revealed at this stage when the top wall panel A is folded about crease line 3 due to its presence in the blank 1 as a slit which opens to create the locking slot 16 when the crease line 3 on which the locking slot is located is bent through 90 degrees.

Finally, top wall panel E is folded along crease line 6 to insert the arrow shaped locking tongue H at the free end of the top wall panel E into the slot 16 to secure the container 2 in the assembled condition as shown in FIGS. 7 and 8. In this way, the top wall panel E is also the closure panel that secures the container 2 in the erected condition.

As best shown in FIG. 8, the assembled container 2 has opposing top and bottom walls of convex dome shape and four vertical side walls of concave shape extending between the top and bottom walls around the entire periphery of the container 2. The terms “top”, “bottom”, “side” refer to the orientation of the container 2 shown in FIG. 8 and the term “vertical” is used to describe the direction parallel to the line between the centre point of the top wall and the centre point of the bottom wall in this orientation.

In this embodiment, the container 2 is assembled from a blank 1 of corrugated material with the fluting arranged to extend longitudinally of the blank where the term longitudinal is defined as that direction perpendicular to the centre point of the arcuate crease lines 3,4,5,6 of each blank 1.

In this way, when the container 2 is assembled, the opposing vertical concave side walls B,D present the fluting in a vertical direction where the term vertical direction is as defined above and, where provided, the opposing concave side walls J,K present the fluting normal to the vertical direction.

As a result, the side walls B,D present a higher resistance to loads in the vertical direction than the side walls J, K. In a modification, the fluting may extend at 45° to the longitudinal direction so that all four side walls B,D,J,K have the same strength and shock-absorbing properties.

Referring now to FIG. 9, a third embodiment of the invention is shown in which the design is modified in such a way that after assembly, the fluting of all four vertical concave side walls is in a vertical direction, thus offering even greater strength to the container.

In this embodiment, the blank 1 comprises first and second blank parts 1′,1″ each with fluting arranged to extend longitudinally of the blank parts 1′,1″ where the term longitudinal is defined as that direction perpendicular to the centre point of the arcuate crease lines of the blank part.

The first blank part 1′ comprises five aligned panels A,B,C,D,E similar to the panels A,BC,D,E of the blank 1 shown in FIG. 5 with an arrow shaped locking tongue H on top wall panel E.

The remaining side wall panels J,K and wing panels F,G of the blank 1 shown in FIG. 5 are now provided by the second blank part 1″ which also comprises five aligned panels with the side wall panels J,K at opposite ends of a centre panel L and wing panels F,G at the free ends of the side wall panels J,K.

The blank 1 may be formed in one piece with edge 21 of panel A of blank part 1′ joined to edge 22 of panel G (or panel F) of blank part 1″ along a perforated line such that the blank parts 1′,1″ can be formed with the fluting extending longitudinally of both blank parts 1′,1″ and the blank parts 1′,1″ separated along the perforated line for assembly of the container as now described.

The centre panel L of the second blank 1″ is placed upon the centre panel C of the first blank part 1′ such that the parts 1′,1″ extend at right angles to each other. In this condition, the blank parts 1′,1″ resemble the blank 1 of FIG. 5 when viewed in plan. At this point, the contents to be packed in the container are placed upon the upper surface of panel L. The second blank part 1″ is then folded about its arcuate crease lines 19,20 until side wall panels J,K form opposed sidewalls and wing panels F,G form a partial roof over the panel L

Panel B of the first blank part 1′ is then folded about arcuate crease line 3 to form a side wall and panel A is folded about crease line 4 to extend over parts of panels F,G and open locking slot 16. Panel D is then folded about crease line 5 to forms a sidewall opposite panel B and panel E is folded about crease line 6 to form the roof wall of the container and insert locking tongue H in locking slot 16 to secure the container in the assembled condition.

The assembled container 2 has a shape similar to that of FIG. 8 but now all the side walls B,D,J,K have the fluting extending in a vertical direction which increases the strength of the container 2.

Referring now to FIG. 10, there is shown a modification to the embodiment of FIG. 9 in which the blank 1 is formed in one piece with two blank parts 1′,1″ connected by a panel M for assembly of a container of similar shape to that shown in FIG. 8 with the fluting extending in a vertical direction on all four side walls B,D,J,K similar to that produced by the blank parts 1′,1″ of FIG. 9 without having to separate the blank parts 1′,1″ for assembly.

In this modification, the fluting direction in each blank part 1′,1″ is again arranged longitudinally as this term has been defined above. Here, panel M is used as a hinge allowing the centre panel L of blank part 1″ to be rotated through 90 degrees and swung over centre panel C of blank part 1′, thereby trapping panel M between panel C and panel L. The remaining assembly procedure follows exactly in accordance with that described above for FIG. 9.

Referring now to FIG. 11, a blank 1 according to a fourth embodiment of the invention is shown for assembly of a container having six side walls of concave shape and opposing roof and floor walls of convex dome shape.

The blank 1 has five aligned panels A,B,C,D,E with a locking tongue H provided at the free end of panel E for insertion in a locking slot 16 formed at the junction of panels A and B.

In addition, panel B has four additional side wall panels N,P,R,S—two on each side—each having a respective wing panel T,U,V,W. The panel E also has four additional locking tongues H—two on each side—for insertion in respective locking slots 16 formed at the junction of each side wall panel N,P,R,S and its associated wing panel T,U,V,W respectively.

The blank 1 is assembled in a similar way to that described above and the top wall panel E is held in position by inserting each of the five locking tongues H into the locking slots 16.

It will be understood that the principle of this embodiment can be applied to containers having any number of side walls. In particular, containers having side walls equal to, or greater than, three are possible although in practice, as the number of concave vertical side walls increases, the number of overlapping roof panels also increases and the point is quickly reached where the contribution of each roof panel to the strength of the container has decreased to the point where the cost of so many overlapping roof panels can no longer be justified in protecting the contents from external shock.

The above-described embodiments show blanks for assembly of containers having a plurality of side walls when viewed from a vertical direction having the appearance of a multi-pointed star with acute angled corners which provide an important feature for protecting the contents of the container.

When the corners of the assembled container are left empty as will typically be the case, the walls of the corner sections become the first points of contact in any lateral movement of the contents of the container resulting from any applied external force that has a horizontal component. In this way, the contents of the container are protected from direct contact with the external force.

The opposing roof and floor walls of convex dome shape provide a similar function against any applied external force that has a vertical component. Furthermore, it will be noticed that where the external force is sufficiently large, the acute angled corners of the side walls or convex domed shape of the opposing roof and floor walls of the container will be crushed before the contents of the container are damaged.

The act of crushing the corners or convex domed faces of the container will absorb and dissipate the external force either fully or partially. It is a feature of this invention that the acute angled corners and the convex domed faces of the assembled container are sacrificed in this way in order to offer maximum protection to the contents of the container.

It has been found that containers assembled from blanks according to this invention offer greater resistance to impact and crushing due to the plurality of vertical concave side walls around the entire periphery and the two convex domed roof and floor walls at the base and top of the container respectively.

It will be seen that when a relatively flat product is packed within a container made from a blank according to the invention, especially if the product is round or oval, it can be held in position within the container without the need for additional internal packaging. By selecting the dimensions of the blank with this in mind, the periphery of the product will make contact with the assembled container at the internal centre points of each concave face. It will thus be held firmly against internal movement within the container at those points least exposed to external forces, due to the concave shape of the vertical wall faces of the container.

A further important protective feature of containers made from blanks according to the invention is the deceleration provided to the contents after the container has been subjected to shock in which acceleration is imparted to the contents due to gravity or other applied force. Any movement of the contents of the container away from the centre of the container will be resisted due to contact of the contents with an internal face of the container.

Due to the inherent design of blanks according to this invention, all internal faces of the container will always present an acute angle to the direction of motion of the contents following a shock to the container. Consequently, resistance to the movement will increase more gradually than would be the case if the resisting internal face or faces were perpendicular to the direction of motion. This more gradual increase of forces resisting the movement of the contents allows containers made from blanks according to the invention to offer improved protection from shock to the contents.

If the radii of the concave vertical wall faces are chosen with such an objective in mind, the assembled containers will fit together when stacked alternately in horizontal and vertical layers. Such a design provides considerable strength and rigidity to the stack which, once stacked upon a pallet, may be wrapped with film by any means without the need for outer shippers made from corrugated board, typically known as cartons. Eliminating the need for cartons as part of the transit packaging system saves considerable cost.

Containers assembled from blanks according to the invention may be of any size provided that the thickness of the sheet material from which the blanks are made has been appropriately chosen. The contents packed in such containers can be of any size or shape and comprise one or more items of similar or different size and shape. It has been found, however, that although the dimensions of the arcuate panels of the blank may differ according to the size of the blank, the curvature of the arcuate crease lines in each arcuate panel are preferably identical in order that the blank can be properly assembled.

If it is wished to pack products that, for any reason, require fittings to be present within the container, for example, to provide additional internal support to the contents, this can be done either by means of separate fittings or by means of additional panels at the extremities of the blank which be folded and formed into fittings as the container is assembled.

The above-described embodiments disclose blanks for assembly of containers secured by one or more locking tongues giving security and tamper evident features. These features are beneficial when the container is to be shipped for example by mail, as many postal services require all packs either to have secure, non-accidentally opening closures or to be secured by means of adhesive or adhesive tape.

It will be understood that the number of locking tongues can be varied according to the size and shape of the container and/or the length of the edge to be closed. Locking tongues of any suitable form can be used that provide evidence of opening or tampering of the container. Such locking tongues are preferably of arrow head shape which allows the tongue to be pushed through a corresponding locking slot.

For some applications, however tamper-evident locking tongues may not be required such as where the container is secured with adhesive or adhesive tape and in this case quick locating tongues (non arrow head type) can be used to hold the container closed whilst it is taped or glued with adhesive.

Finally, it will be understood that features of each embodiment described herein may be used separately or in combination with any feature of the other embodiments to provide blanks and containers erected from such blanks having the advantages and benefits described herein. For example, in FIGS. 1 to 4, the roof panel E may be provided with one or more locking tongues to be inserted in locking slots similar to FIGS. 5 to 11. 

1. A blank from which may be formed a protective enclosed tamper evident container, the blank being made of shape-retaining material and comprising a main section which has five aligned panels, a first of these panels defining a first main wall of the container, second and third of these panels, each defining a side wall of the container, are connected to opposite ends of said first panel, fourth and fifth of these panels, each defining a portion of a second main wall of the container, are connected to said second and third panels at an end that opposes the end connected to said first panel, wherein the second main wall is, when erected, opposed to the first main wall, with said fourth and fifth panels being dimensioned to overlap free end of one panel over free end of the other panel, the side wall panels are defined between first and second arcuate crease lines curved towards each other such that each side wall panel is almost elliptical, and the blank includes a closure panel on each side of the main section, wherein each closure panel is provided with a tongue that is, when the container is erected, received in a respective matching slot provided in one of the main walls of the container in order to hold the container in a closed position, and each slot being so shaped and dimensioned that, once entered, neither tongue can be removed without leaving evidence of tampering, and in which no adhesive is required during the erection of the blank in order to hold the container in its closed position.
 2. A blank as claimed in claim 1, wherein the closure panels are provided at opposing sides of the first main wall that are not connected to the second and third panels, and the slots are provided in the outermost panel of the second main wall.
 3. A blank as claimed in claim 1, wherein the closure panels are provided at opposing sides of the outermost panel of the second main wall and the slots are provided in the first main wall.
 4. A blank as claim in claim 1, wherein a first closure panel is provided at one side of the first main wall that is not connected to the second and third panels, and the slot engaged by the tongue of the first closure panel is provided in the outermost panel of the second main wall, and a second closure panel is provided at one side of the outermost panel of the second main wall on the opposite side of the main section to the first closure panel, and the slot engaged by the tongue of the second closure panel is provided in the first main wall.
 5. A blank as claimed in claim 1, wherein the material used for the blank is fluted board, the fluting being aligned generally from end to end of the aligned panels of the blank, and thus generally normal to the arcuate crease lines.
 6. A blank as claimed in claim 1, wherein the material used for the blank comprises a second layer attached to the inside surface of the blank in order to provide the erected closed container with desired properties.
 7. A blank as claimed in claim 6, wherein the second layer is an insulating material and/or a protective material.
 8. A blank as claimed in claim 7 wherein the second layer is selected from the group comprising bubble wrap, cradle wrap or other filmic materials incorporating sealed bags or bubbles containing air or other gases.
 9. A blank as claimed in claim 1, wherein the degree of curvature of the arcuate crease lines is generally in a ratio of centre point height to outer limit height of from 4:1 down to 1.5:1.
 10. A blank as claimed in claim 1, wherein, to improve the ease with which the blank can be folded, the crease lines have been perforated.
 11. A blank as claimed in claim 10, wherein the perforation has been carried out using lasers.
 12. A blank as claimed in claim 1, wherein the closure panels are connected to the main section of the blank at an edge defined by first and second straight crease lines.
 13. A blank as claimed in claim 1, wherein the closure panels are connected to the main section of the blank via side wall panels defined by first and second arcuate crease lines.
 14. A protective enclosed tamper evident container made by erecting a blank as claimed in claim
 1. 